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【medical-news】实验室培养出人类肝脏
Lab grows human liver
In the near future you might not have to wait for a liver for transplant, one will be grown for you
Fiona MacRae, Daily Mail
Scientists have grown a miniature human liver from stem cells, which can immediately be used to test drugs, reducing the need for animal experiments.
Within 15 years the experts hope to provide whole sections which can be used to repair damaged livers. And some years after that, they expect to produce entire organs for lifesaving transplants.
The technique, which created the mini-liver, the size of a 25 paise coin, will be developed to create a full-size functioning version.
In what was described as a 慐ureka moment?by researchers from UK-based Newcastle University, the tissue was created from blood taken from umbilical cords just a few minutes after birth.
In its current form, use of the mini organ in drug trials could avert disasters in which human volunteers suffer appalling damage.
Within five years, pieces of artificial tissue could be used to repair livers damaged by injury, disease, alcohol abuse and paracetamol overdose.
The transplant breakthrough will come too late for patients currently awaiting a liver swop. But for future victims of disease, the chances will be far better.
HOW THE SCIENTISTS DID IT?/b>
The liver tissue is created from stem cells ?blank cells capable of developing into different types of tissue ?found in blood from the umbilical cord.
Working in collaboration with experts from the US, the Newcastle scientists have succeeded in separating the stem cells from blood removed from the umbilical cord minutes after birth.
They are then placed in a 慴ioreactor??a piece of electrical equipment developed by NASA to mimic the effects of weightlessness. Inside this, the freedom from the force of gravity allows them to multiply more quickly than usual.
Various hormones and chemicals are then added to coax the stem cells into turning into liver tissue. Other researchers have grown heart tissue from stem cells, and injections of stem cells have successfully been used to strengthen damaged heart muscle.
WHAT IT MEANS FOR MEDICINE SCIENCE
Currently, experiments on new drugs are carried out in the test tube, before being tried out first on animals, then on humans. The effects of these tests, however, can be catastrophic at times wherein volunteers are left fighting for their lives. But lab-grown human tissue could iron out any difficulties before drugs are given to humans.
The researchers envisage sections of artificial liver being used to keep patients needing transplants alive ?in much the same way as a dialysis machine is used to treat kidney failure. This technique would take advantage of the liver抯 remarkable ability to regenerate itself.
Patients would be hooked up to an artificial liver which would take over all the functions usually carried out by their own liver.
With several 慸ialysis?sessions a day over a period of several months, the patient抯 own liver would be given enough resting time to regenerate and repair any damage. Alternatively, vital months could be bought in search for a suitable donor for transplant.
THE FUTURE
While other researchers have created liver cells using stem cells taken from embryos, the Newcastle team are the first to create sizeable sections of tissue from stem cells from the umbilical cord.
They believe their technique is better suited to growing larger sections of tissue.
Use of cord stem cells is also more ethically acceptable than the use of embryo stem cells ?a process which leads to the death of the embryo.
The Newcastle researchers foresee a time when cord blood from millions of babies born each year is banked, creating a world-wide donor register for liver dialysis and transplant.
Computerised registers could then be created to match the cord blood with tissue type or immune system of patients with liver problems.
The method is already used to treat leukaemia, with more and more parents freezing their children抯 cord blood in such banks around the world.
揙ne hundred million children are born around the world every year ?that is 100 million different tissue types,?said Colin McGuckin, professor of regenerative medicine at Newcastle University. 揥ith that number of children being born every year, we should be able to find a tissue for me and you and every other person who doesn抰 have stem cells banked.?
Co-researcher Dr Nico Forraz said: 揙ur dream is that every city would have such a bank. If you could type the blood, all you would have to do is dial it up on your computer and fly it from Bristol to ewcastle or even Newcastle to Mumbai.?/p> http://www.dxy.cn/bbs/post/view?bid=116&id=7401983&sty=1
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作者:admin@医学,生命科学 2010-10-15 05:11
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